Nov. 24, 2003

LAWRENCE -- Research discoveries by University of Kansas biologists are helping state and federal wildlife officials bring the endangered Topeka shiner minnow back from the brink of extinction.

One key was confirmation by Scott Campbell, research associate with the Kansas Biological Survey at KU, and his colleagues that the presence of sunfish in the right environments increased the minnow's natural rate of reproduction.

As a result, KU biologists have been able to propagate thousands of shiners for use in research from an initial stock of 300 taken from one Kansas creek and have provided them for counterparts at Kansas State University and in the Missouri Department of Conservation for their own studies of this "little-understood" fish, Campbell said.

The 3-inch Topeka shiner, a member of the minnow family Cyprinidae, lives about three years and is found in the calmer runs and pools in the headwaters of certain small streams in Kansas, where it's most common, as well as in limited places in Missouri, Iowa, Nebraska, South Dakota and Minnesota.

"In summer months males display bright red fins and iridescent bluish bodies, making them one of the more strikingly beautiful fishes in our state," Campbell said.

Developing techniques to propagate Topeka shiners is important to their recovery, considering that the Topeka shiner's range has declined by nearly 90 percent in the past few decades and it was added to the federal endangered species list in 1998, Campbell said. It now occurs in only a small fraction of places where it once was common and even has vanished from the Topeka creek where the first Topeka shiners to be described by biologists were identified in 1884.

The U.S. Fish and Wildlife Service and the Kansas Department of Wildlife and Parks funded the KBS study. The Kingsbury Family Foundation through the KU Endowment Association provided additional funding to support graduate research assistantships.

In the study, Campbell; Jerry deNoyelles, associate director of KBS and KU professor of ecology and evolutionary biology; and KU graduate students Cody Szuwalski and Bridgett Chapin provided a variety of habitats in a dozen experimental ponds and several large tanks at the KU Field Station and Ecological Reserves north of Lawrence to determine the shiner's ideal spawning conditions.

They discovered the tiny fish likes a bed of clean gravel and calm water and it reproduces much better when orange-spotted or green sunfish are present.

"This may at first appear counterintuitive, since the sunfish are predators known to prey on minnows such as the Topeka shiner," Campbell said. "However, and apparently in spite of this risk, Topeka shiners have been observed to dart in and lay their eggs on the nests of spawning sunfish."

Since sunfish fiercely guard their nests and fan them attentively with their fins to keep them silt-free and well oxygenated, perhaps the sunfish unwittingly protect not only their own eggs but also those of the interloping shiners, he said.

"The results of the current research confirm we are grasping the fact that in some way the sunfish confer a kind of reproductive advantage to the Topeka shiner," Campbell said. "That the shiners apparently depend on other fish species for reproduction demonstrates the importance of diversity in a fish community and provides additional evidence that nature is wondrously full of such complex relationships that humans are only beginning to appreciate.

"When a natural fish community becomes altered or diminished in some way and possibly loses the diversity of species that supports it, the effects can be quick and unpredictable."

What is happening to the Topeka shiner is an indicator of the broad-scale environmental changes that are greatly affecting aquatic communities throughout much of the Great Plains, Campbell said. Genetic diversity diminishes as species go extinct or as existing populations become increasingly isolated. Several factors seem to have contributed to the shiner's decline, including loss of habitat, diminished water quality and the wide introduction of predaceous fish, such as largemouth bass, Campbell said.

There's strong evidence that largemouth bass were responsible for decimating the fish community in Wallace County's Willow Creek, a harsh environment for any aquatic species in extreme western Kansas, Campbell said. Protecting the Willow Creek population is of particular interest to scientists because it exists in isolation, nearly 250 miles from other known populations, and its members are genetically different from other Topeka shiners.

Topeka shiners had lived in the pools of Willow Creek for perhaps thousands of years as part of an "ecologically perfect" fish community, according to Vernon Tabor, endangered species coordinator for the U.S. Fish and Wildlife Service. Tabor also serves on the National Topeka Shiner Recovery Team and is an active collaborator in KU's current research effort.

At least six species of minnows, two species of sunfish, a darter, black bullhead catfish and plains killifish had thrived in Willow Creek, according to regular sampling that has occurred there for more than 60 years. But after a single winter, the Topeka shiners and several other species of minnows were nearly gone. Coincidentally, largemouth bass had been introduced to the creek the previous year, Tabor said. Tabor, Campbell and others believe that introduced bass, as well as other environmental factors, may be largely responsible for the decline of wild populations of the Topeka shiner, Campbell said. Predation will be among the many new questions addressed by continuing research at KU using the stock of fish being produced at KU's field station.

"Across its entire range the Topeka shiner still faces a long 'upstream' battle for survival and will require the help of humans who must significantly improve habitat conditions and the water quality of our streams for all who share it," Campbell said. "However, thanks to the efforts of concerned citizens and scientific research at KU and elsewhere, the shiner's future may be getting a little brighter.

"People may wonder why I think saving the Topeka shiner is worth the effort," Campbell said, adding that it's more than scientific interest. "When I consider the fact that this little fish has managed to survive for countless generations, perhaps thousands of years, here on the prairie, I respect and marvel at that and take great comfort in knowing many other Kansans share that feeling as well."

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